In a move to punish Russia's hostile takeover of Crimea, the White House on Thursday announced a second round of sanctions against 20 Russians and a St. Petersburg bank. This builds on asset freezes and visa bans President Obama ordered Monday against 11 Russian and Ukraine officials, which some didn't take very seriously, especially Russian Deputy Prime Minister Dmitry Rogozin, one of the officials targeted. He taunted Obama on Twitter for letting "some prankster" craft his sanctions.

At least publicly, U.S. officials say the sanctions are meant to force Russia to return Crimea to Ukraine. Privately, however, they probably know that is unlikely to happen; Russia President Vladimir Putin is too heavily invested politically in Crimea's annexation to be moved by economic punishment.

Instead, U.S. sanctions will seek to accomplish less ambitious (but more realistic) goals: For one, such measures could deter Russia from encroaching further into Ukraine. Also, they would signal that land grabs like Crimea come with a price and therefore could discourage foreign capitals considering similar acts of aggression from following Putin's lead.